Marine mammal behavior researchers have recently captured on film an adult grey seal both drowning a pup and then subsequently cannibalizing it. The experts with Durham University caught the event as it unfolded on the Isle of May, a 1.1 mile long island off the eastern coast of Scotland. Throughout the course of one week in December of 2014, they witnessed the same male grey seal cannibalize 5 different pups.
On one occasion (the one videoed below), the seal was seen dragging the pup to a shallow pool and submerging it until it drowned so as to eat it. Their study goes on to describe the finding of 14 pup carcasses in the area featuring “traumatic injuries” believed to have been sustained by an adult of the same species. At least a dozen of these carcasses were partially devoured.
The reports indicate that such a display of cannibalism may prove these seals are altering their diets from largely fish and crustaceans to other marine mammals because of rapid environmental changes. Surprisingly, this isn’t the first documented example of bad behavior in the species. Just two years ago, seals were blamed for wiping out hundreds of porpoises and have previously even been discovered raping penguins.